but doesn't promote abstinence because it's based on the assumption that humans are sexual beings that have no reason to not have sex.
Fine with everything else but I don't see any good reasoning behind the anti-abstinence brigade. I'd be the last person in the world to take the side of church for example, but it still remains as the most effective means of contraception; unless you are, ironically, of 'the Church' for example, in which case it would appear to only have a 99.99999% success rate with the exception being Mary and her apparent parthenogenesis. Should abstinence be taught as the only acceptable means of contraception? Of course not. Should it be taught alongside the others? Absolutely.